[2/3] clk: tegra: T114: add DFLL source clocks

Commit Message

Paul Walmsley June 7, 2013, 12:19 p.m. UTC

Add the input clocks needed by the DFLL IP blocks.  Initialize them to
51MHz (as required by the DFLL GFD) and to use the PLL_P clock source.

This patch is a collaboration with Peter De Schrijver
<[e-mail]>.

Thanks to Laxman Dewangan <[e-mail]> for identifying the
requirement to keep the DFLL clocks enabled to resolve PWR_I2C timeout
issues.

Signed-off-by: Paul Walmsley <[e-mail]>
Cc: Peter De Schrijver <[e-mail]>
Reviewed-by: Andrew Chew <[e-mail]>
Cc: Matthew Longnecker <[e-mail]>
Cc: Laxman Dewangan <[e-mail]>
---
 drivers/clk/tegra/clk-tegra114.c |   11 +++++++++++
 1 file changed, 11 insertions(+)

Comments

Stephen Warren June 7, 2013, 4:53 p.m. UTC | #1

On 06/07/2013 06:19 AM, Paul Walmsley wrote:
> Add the input clocks needed by the DFLL IP blocks.  Initialize them to
> 51MHz (as required by the DFLL GFD) and to use the PLL_P clock source.
> 
> This patch is a collaboration with Peter De Schrijver
> <[e-mail]>.
> 
> Thanks to Laxman Dewangan <[e-mail]> for identifying the
> requirement to keep the DFLL clocks enabled to resolve PWR_I2C timeout
> issues.

> diff --git a/drivers/clk/tegra/clk-tegra114.c b/drivers/clk/tegra/clk-tegra114.c

> @@ -792,6 +794,7 @@ enum tegra114_clk {
>  	audio1, audio2, audio3, audio4, spdif, clk_out_1, clk_out_2, clk_out_3,
>  	blink, xusb_host_src = 252, xusb_falcon_src, xusb_fs_src, xusb_ss_src,
>  	xusb_dev_src, xusb_dev, xusb_hs_src, sclk, hclk, pclk, cclk_g, cclk_lp,
> +	dfll_ref = 264, dfll_soc,

Those values need to be added to the DT binding documentation, or rather
the header file that now defines the constants for that binding.

BTW, I was rather hoping that Hiroshi would have converted the clock
drivers to actually use that header file by now... Then this requirement
would have been a lot more obvious. Hiroshi, are patches for that coming
soon? Paul, if not, are you able to do that?

For reference, include/dt-bindings/clock/tegra*-car.h.

Patch

diff --git a/drivers/clk/tegra/clk-tegra114.c b/drivers/clk/tegra/clk-tegra114.c
index c6e35d4..b35c78d 100644
--- a/drivers/clk/tegra/clk-tegra114.c
+++ b/drivers/clk/tegra/clk-tegra114.c
@@ -269,6 +269,8 @@ 
 #define CLK_SOURCE_I2CSLOW 0x3fc
 #define CLK_SOURCE_SE 0x42c
 #define CLK_SOURCE_MSELECT 0x3b4
+#define CLK_SOURCE_DFLL_REF 0x62c
+#define CLK_SOURCE_DFLL_SOC 0x630
 #define CLK_SOURCE_SOC_THERM 0x644
 #define CLK_SOURCE_XUSB_HOST_SRC 0x600
 #define CLK_SOURCE_XUSB_FALCON_SRC 0x604
@@ -792,6 +794,7 @@  enum tegra114_clk {
 	audio1, audio2, audio3, audio4, spdif, clk_out_1, clk_out_2, clk_out_3,
 	blink, xusb_host_src = 252, xusb_falcon_src, xusb_fs_src, xusb_ss_src,
 	xusb_dev_src, xusb_dev, xusb_hs_src, sclk, hclk, pclk, cclk_g, cclk_lp,
+	dfll_ref = 264, dfll_soc,
 
 	/* Mux clocks */
 
@@ -1796,6 +1799,8 @@  static struct tegra_periph_init_data tegra_periph_clk_list[] = {
 	TEGRA_INIT_DATA_MUX("i2cslow", NULL, "i2cslow", mux_pllp_pllc_clk32_clkm, CLK_SOURCE_I2CSLOW, 81, &periph_u_regs, TEGRA_PERIPH_ON_APB, i2cslow),
 	TEGRA_INIT_DATA_INT8("se", NULL, "se", mux_pllp_pllc2_c_c3_pllm_clkm, CLK_SOURCE_SE, 127, &periph_v_regs, TEGRA_PERIPH_ON_APB, se),
 	TEGRA_INIT_DATA_INT_FLAGS("mselect", NULL, "mselect", mux_pllp_clkm, CLK_SOURCE_MSELECT, 99, &periph_v_regs, 0, mselect, CLK_IGNORE_UNUSED),
+	TEGRA_INIT_DATA_MUX("dfll_ref", "ref", "t114_dfll", mux_pllp_clkm, CLK_SOURCE_DFLL_REF, 155, &periph_w_regs, TEGRA_PERIPH_ON_APB, dfll_ref),
+	TEGRA_INIT_DATA_MUX("dfll_soc", "soc", "t114_dfll", mux_pllp_clkm, CLK_SOURCE_DFLL_SOC, 155, &periph_w_regs, TEGRA_PERIPH_ON_APB, dfll_soc),
 	TEGRA_INIT_DATA_MUX8("soc_therm", NULL, "soc_therm", mux_pllm_pllc_pllp_plla, CLK_SOURCE_SOC_THERM, 78, &periph_u_regs, TEGRA_PERIPH_ON_APB, soc_therm),
 	TEGRA_INIT_DATA_XUSB("xusb_host_src", "host_src", "tegra_xhci", mux_clkm_pllp_pllc_pllre, CLK_SOURCE_XUSB_HOST_SRC, 143, &periph_w_regs, TEGRA_PERIPH_ON_APB | TEGRA_PERIPH_NO_RESET, xusb_host_src),
 	TEGRA_INIT_DATA_XUSB("xusb_falcon_src", "falcon_src", "tegra_xhci", mux_clkm_pllp_pllc_pllre, CLK_SOURCE_XUSB_FALCON_SRC, 143, &periph_w_regs, TEGRA_PERIPH_NO_RESET, xusb_falcon_src),
@@ -2057,6 +2062,10 @@  static const struct of_device_id pmc_match[] __initconst = {
 	{},
 };
 
+/*
+ * dfll_soc/dfll_ref apparently must be kept enabled, otherwise I2C5
+ * breaks
+ */
 static __initdata struct tegra_clk_init_table init_table[] = {
 	{uarta, pll_p, 408000000, 0},
 	{uartb, pll_p, 408000000, 0},
@@ -2072,6 +2081,8 @@  static __initdata struct tegra_clk_init_table init_table[] = {
 	{i2s2, pll_a_out0, 11289600, 0},
 	{i2s3, pll_a_out0, 11289600, 0},
 	{i2s4, pll_a_out0, 11289600, 0},
+	{dfll_soc, pll_p, 51000000, 1},
+	{dfll_ref, pll_p, 51000000, 1},
 	{clk_max, clk_max, 0, 0}, /* This MUST be the last entry. */
 };